Everything you've ever wondered about your aquarium.

Temperature drives metabolism, oxygen levels, and disease resistance in fish. Even small swings can stress livestock and crash sensitive corals or shrimp, which is why continuous monitoring is more useful than a daily glance at a thermometer.

Most tropical community tanks do best between 75–80°F (24–27°C). Discus and some species prefer the warmer end; many tetras and rasboras tolerate slightly cooler. The key is stability, not the exact number.

Most reef keepers target 76–80°F (24–27°C). Some SPS-dominant systems run a couple of degrees cooler to slow metabolism and improve coloration. Stability within ±0.5°F is more important than the absolute target.

• → Read: Reef tank temperature stability
• → See how Tank Commander helps reef tanks

Goldfish are coldwater fish and prefer 65–72°F (18–22°C). Sustained temperatures above 75°F stress them and increase disease risk. They generally do not need a heater unless your room gets cold.

Bettas thrive between 76–82°F (24–28°C). Below 74°F they become lethargic and prone to fin rot. A small, reliable heater is essential for their health.

Axolotls are cold-water amphibians and need water between 60–68°F (16–20°C). Above 74°F they become severely stressed and prone to fungal infection. They never need a heater.

Most African cichlid (Malawi, Tanganyika) setups do well at 76–82°F (24–28°C). Tanganyikans tend to prefer the cooler end of that range. Stability and good oxygenation matter as much as the exact value.

For most tanks, ±1°F (±0.5°C) is plenty. What really matters is consistency: a probe that drifts will mislead you over weeks, even if it looks accurate today. Continuous, drift-resistant probes are far more useful than glass thermometers checked once a day.

Common causes are direct sunlight on the tank, lights heating the water, room HVAC cycling, and undersized heaters. Even ‘stable’ rooms see 1–3°F swings that fish feel. A controller that logs temperature continuously makes the pattern obvious.

Increase surface agitation with a fan over the water (evaporation cools the tank by several degrees), open the canopy, and run lights at night when the room is cooler. For larger or sensitive tanks, a chiller on a temperature-triggered outlet is the most reliable solution.

Use a heater rated for your tank size — undersized heaters run constantly, oversized ones overshoot. Pairing the heater with a smart outlet that cuts power above your set point gives you a hard safety stop in case the heater’s built-in thermostat fails.

The heater keeps running and can boil the tank within hours, killing fish and corals. This is one of the most common ways tanks crash. A second, independent temperature controller cutting the outlet at a safe ceiling prevents the disaster.

• → Read: How to prevent heater failure on a reef tank
• → How outlet automation works

Temperature slowly drifts toward room temperature. Tropical fish become sluggish, immune systems weaken, and ich often follows. Continuous monitoring with a low-temperature alert lets you swap the heater before livestock suffer.

Two smaller heaters split the load, give redundancy, and reduce the consequences if one fails on. It’s a popular setup for medium and large tanks. You still want a controller monitoring temperature and cutting power on overshoot.

Possible causes: the heater is undersized for the tank, the room is colder than expected, the heater is failing, or a previous owner set the dial low. Logging temperature continuously and watching when the heater kicks on helps diagnose which it is.

Use a controller that sends push notifications to your phone the moment a parameter leaves a safe range. Tank Commander watches temperature in real time and pushes an alert plus optional local alarm when it drifts past your thresholds.

• → See Tank Commander pricing
• → Setup guide — install in 15 minutes

It depends on tank size and room temperature, but typical tropical tanks lose roughly 1–2°F per hour in a cool room. Larger tanks lose heat more slowly. The bigger danger after a power outage is oxygen depletion, not temperature.

Yes. Sudden swings of more than 2–3°F over a short period can suppress fish immune systems and trigger disease outbreaks. Keeping temperature within a tight band is one of the simplest ways to keep fish healthy.

Tropical species become stressed below 70°F (21°C) and suffer above 86°F (30°C); coldwater fish suffer above 75°F (24°C). Long-term exposure outside their range causes immune suppression and death. Real-time alerts let you act before that point.

Warmer water holds less dissolved oxygen. A tank at 84°F holds noticeably less O₂ than the same tank at 76°F, which compounds heat stress. Adding surface agitation when temperature climbs is a smart automation rule.

Higher temperatures (and higher pH) shift more ammonia into the toxic NH₃ form. A heated tank with elevated pH can cross from safe to dangerous quickly during a mini-cycle, even at the same total ammonia reading.

Lights off means the main heat source is gone, and many homes drop by several degrees overnight. Insulated cabinets, properly sized heaters, or running the heater on a temperature-triggered outlet keeps the swing small.

Yes — especially metal halides, hot LED fixtures, and cabinets with poor ventilation. Some tanks run 2–4°F warmer with lights on. A surface fan tied to a temperature threshold counteracts the rise without manual intervention.

If your room consistently exceeds your target tank temperature in summer, or you keep cool-water species like axolotls in a warm climate, yes. Otherwise, a fan on a temperature-triggered outlet is usually enough.

A premium temperature probe sits in the tank and streams readings to the controller continuously. The live value appears on the on-device display, in the app, and feeds any automations or alerts you set up.

Yes. Plug the heater into one of the six smart outlets and tie the outlet to the temperature reading — for example, ‘cut power if tank exceeds 80°F.’ This protects against stuck-on heater failures, the single most common cause of cooked tanks.

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• → Compare to Neptune Apex

pH measures how acidic or basic the water is, on a scale of 0 to 14. Fish, plants, corals, and bacteria all evolved within narrow pH bands. Swings or drift outside that band stresses livestock and disrupts the nitrogen cycle.

Most community tropicals do well between 6.8 and 7.8. Stability within that range matters more than landing on a specific number. Sudden changes are far more dangerous than the ‘wrong’ stable value.

Planted tanks generally run between 6.5 and 7.5, often a touch lower than non-planted setups due to CO₂ injection. Stable pH during the photoperiod is the main goal — large daily swings stress fish and shrimp.

• → Read: Understanding pH swings in planted tanks
• → See how Tank Commander helps planted tanks

Most reef keepers aim for 8.1–8.4. Calcification and coral growth slow as pH drops. Continuous pH logging is the easiest way to spot problems — a daytime peak below 8.0 usually means CO₂ buildup somewhere.

Malawi and Tanganyika cichlids prefer 7.8–8.6. Aragonite substrates and crushed coral help hold pH up. Continuous monitoring confirms you’re actually in range, not just trusting an old test kit.

Blackwater setups for species like discus, wild bettas, or chocolate gouramis target pH 5.5–6.5. The water is naturally soft and acidic; tannins from leaves and driftwood help maintain it. Real-time monitoring catches a slide before it becomes a crash.

Plants stop photosynthesizing in the dark and instead respire, releasing CO₂ into the water. CO₂ forms carbonic acid, which pulls pH down — sometimes by 0.5 or more between lights-out and lights-on. A 24-hour pH chart shows this immediately.

• → Read: Understanding pH swings in planted tanks
• → Planted-tank automation guide

Daily reef pH swings are normal and driven by photosynthesis on the reef and in your home. Lights and refugium activity raise pH; closed houses or CO₂-rich rooms lower it. Big swings (>0.3) usually point to ventilation, alkalinity, or skimmer issues.

A pH crash is a sudden, large drop — often into the 5s in freshwater or below 7.7 in marine. It usually follows an alkalinity collapse from infrequent water changes, dying livestock, or CO₂ overdose. Continuous pH and temperature monitoring catches the slide early enough to react.

• → Read: Why continuous monitoring beats spot testing
• → See Tank Commander features

If you’re hand-testing, at least weekly, and after any major change. With a continuous pH probe you no longer ‘test’ — you watch a graph that tells you the pattern, not just a single reading.

Common causes: hard tap water, crushed coral or aragonite substrate, limestone rocks, or a low-CO₂ environment. None of these are emergencies on their own, but they may not match the species you keep.

Causes include soft tap water, lots of driftwood or leaf litter, build-up of organic acids between water changes, or CO₂ injection in a planted tank. Check alkalinity (KH) — low KH lets pH wander.

Sustained pH outside a species’ range causes chronic stress and shortens lifespan. High pH also makes ammonia far more toxic at the same concentration, so a high-pH tank with a hidden mini-cycle is especially dangerous.

Yes — and very low pH stalls the nitrogen cycle, because the bacteria that consume ammonia and nitrite slow down below 6.0. You can end up with dropping pH and rising ammonia at the same time.

Yes. CO₂ dissolves into water as carbonic acid and lowers pH. In a planted tank, this is normal during the photoperiod and bounces back overnight. If pH falls and stays down, the injection is over-tuned.

Yes — sodium bicarbonate raises both pH and KH. It’s a quick fix in emergencies but should be added slowly and ideally outside the tank in fresh water during a water change. Big, fast pH changes are more harmful than the original wrong value.

During the day, plants pull CO₂ from the water, raising pH. At night they release CO₂, lowering it. The pattern is most visible in heavily planted tanks with strong light.

Driftwood, almond leaves, and peat release tannins and humic acids that lower pH and soften water. This is desirable for blackwater fish and shrimp; less so for cichlids or corals.

Inert substrates like quartz sand or pool-filter sand do not change pH. Aragonite, crushed coral, and limestone raise pH and KH. ‘Active’ planted-tank soils like ADA Amazonia lower pH.

Ammonia exists as harmless ammonium (NH₄⁺) at low pH and toxic ammonia (NH₃) at high pH. The same total ammonia value is far more dangerous in a marine tank at pH 8.2 than in a soft-water tank at pH 6.5.

A high-quality pH probe sits in your sump or display tank and streams a live reading to the controller. You see the value on the device, on your phone, and as a continuous chart so trends are obvious.

Yes. Set a low pH threshold in the app and Tank Commander pushes an alert and sounds a local alarm if your reading crosses it. You can do the same on the high side for marine and African cichlid tanks.

• → See setup guide
• → Tank Commander reviews

Yes. Plug the CO₂ solenoid into a smart outlet and tie it to the pH reading — for example, cut CO₂ if pH falls below 6.6. This is a hard safety stop on top of your normal solenoid timer.

• → Pre-order Tank Commander
• → For planted tanks

Most pH probes drift slowly and benefit from a calibration check every 2–3 months using two-point calibration solutions. Tank Commander reminds you when calibration is due based on usage.

Yes — fresh tap water has different pH and KH from tank water, and probes briefly see the mix. Readings settle within minutes once flow resumes. Avoid making decisions from a reading taken mid-water change.

pH measures how acidic or basic the water is right now. KH (carbonate hardness, or alkalinity) measures the water’s ability to resist pH change. Low KH lets pH swing widely; healthy KH keeps pH stable.

TDS stands for total dissolved solids — a measure of all the minerals, salts, and organics dissolved in the water. It’s reported in ppm and is a quick proxy for overall water quality and consistency between water changes.

• → Read: TDS explained for aquariums

Most freshwater fish are comfortable across a wide TDS range, typically 200–500 ppm. The exact value matters less than stability. Rising TDS between water changes signals build-up of waste and minerals.

Caridina shrimp typically want 100–160 ppm; Neocaridina prefer 200–300 ppm. Continuous monitoring is far more useful than weekly hand-testing because shrimp are sensitive to fast TDS changes.

Most non-shrimp planted tanks run 150–350 ppm. Higher TDS is fine if it comes from fertilizers, but if it’s climbing because of waste, your water-change schedule is too light.

Rising TDS between water changes is normal — you’re adding food, ferts, and the fish are producing waste. Faster-than-usual rises can mean uneaten food, a dead fish, or evaporation concentrating minerals. Logging TDS makes the pattern obvious.

Minerals from food, fertilizers, top-off water, and broken-down waste accumulate over time. Water changes dilute them. A continuous TDS reading shows you exactly when the next change is due.

Salinity is the concentration of dissolved salts in the water. Marine fish, inverts, and corals are adapted to a narrow band; drift kills sensitive species. Continuous salinity monitoring is the closest thing reef-keepers have to a safety net.

Most reef keepers target 1.025 specific gravity (about 35 ppt). Fish-only tanks tolerate slightly lower (1.020–1.022). Stability matters more than the exact target, especially for SPS corals and inverts.

• → See how Tank Commander helps reef tanks
• → Automating a marine tank — guide

Salinity (ppt) is a direct measure of dissolved salts; specific gravity (sg) compares the density of saltwater to fresh water. They’re related but not identical, and salinity is generally the more accurate target.

A refractometer is a manual optical tool — accurate but needs calibration and can only give you a single reading. A conductivity probe streams a continuous salinity value to a controller, which is dramatically safer for reef tanks.

Almost always evaporation (rising salinity) or a malfunctioning auto top-off (falling salinity from overshooting). Continuous monitoring catches drift hours before livestock react.

• → Continuous monitoring vs spot testing
• → Salinity monitoring with Tank Commander

An ATO replaces evaporated fresh water, holding salinity stable. If the ATO sticks on or overshoots, salinity falls fast. Tying the ATO outlet to a salinity threshold is a strong second line of defense.

• → Automating a marine tank — full guide
• → For saltwater fish-only

Yes — uncovered tanks in dry climates can evaporate enough water in a day to noticeably raise salinity. This is why reef keepers run automatic top-offs and watch salinity continuously.

Replace small amounts of tank water with RO/DI water over hours, not minutes. Aim for a salinity change of no more than 0.001 sg per hour for sensitive corals and inverts. Continuous monitoring lets you see the slope live.

Pre-mix a higher-salinity batch with quality salt mix and dose it in slowly over hours. Avoid pouring dry salt into the display — it creates damaging local hot spots. Watch the live salinity reading until you’ve hit your target.

RO/DI water should read at or near 0 ppm. A rising TDS from your RO/DI output means your DI resin is exhausted and minerals are passing through. Catching this early protects sensitive tanks from chloramine, copper, or silicate ingress.

Sediment and carbon stages typically last 6 months; membranes last 1–2 years; DI resin should be replaced when post-filter TDS climbs above 0–1 ppm. A continuous TDS reading takes the guesswork out.

Plants need minerals, but extremely high TDS (often from old water) signals build-up of waste rather than useful nutrients. If TDS climbs steadily despite ferts, your water-change frequency is too low.

Yes. Sudden TDS swings interfere with shell formation and can kill shrimp during a molt. Stability is more important than exact value, which is why continuous monitoring is so valuable for shrimp keepers.

A conductivity probe in your sump or display streams a live salinity reading. You can view it on the device, in the app, and set alerts for any drift outside your safe range.

Yes. Set a high and low salinity threshold and Tank Commander pushes a notification and sounds a local alarm the moment the reading crosses either. You can also tie an outlet (like the ATO) to the same value.

Yes. For example, a top-off pump can be set to run only while salinity is above a target, and stop the moment it drops to the safe value. This prevents the classic ‘ATO got stuck on’ disaster.

Yes — saltwater is dramatically more conductive, which is why salinity probes use conductivity to measure salt content. It’s also why stray voltage in marine tanks demands more attention.

Yes. Tank Commander has profiles for marine and freshwater so the appropriate parameters and ranges are shown for your tank type. The same hardware works for both.

No — TDS is a useful overall water-quality indicator but it doesn’t tell you which dissolved substance is changing. You still want pH (continuously) and periodic KH tests, especially in reef tanks.

Most leaks come from a few sources: aged silicone seams, hairline cracks from impacts or stress, failed plumbing fittings, overflow boxes, or sumps that overflow during a power cycle. Even a small drip can soak floors and damage drywall before it’s noticed.

• → Read: A guide to aquarium leak detection

Silicone failure on older tanks, cracked bulkheads, kinked or detached return lines, overflows that siphon back during a power outage, and ATO pumps that stick on. Many of these are silent — you only notice when there’s already a puddle.

Look for damp areas around the stand, salt creep on the floor, or unexplained drops in tank level. The reliable answer is a leak sensor — it tells you before you notice anything.

Even a slow leak can cause thousands of dollars in flooring, drywall, and electrical damage, plus the obvious risk to fish. Catching it within minutes vs. hours is the difference between mopping up and replacing your floor.

Inside the stand on the lowest point of the cabinet, behind the tank where overflow boxes can spill, near the sump, and near any external pumps or RO/DI lines. The goal is to catch water at its first contact point.

Avoid placing sensors directly inside the sump (always wet) or somewhere that gets normal splash from skimmers or wavemakers. You want them dry by default so any water means a real problem.

A small water-detecting sensor lives where you choose. The moment it senses water, the controller sounds a local alarm on the device and pushes a notification to your phone — instantly, with no cloud round-trip required.

• → Pre-order Tank Commander
• → Setup guide — install in 15 minutes

Yes. The on-device alarm is loud enough to hear from the next room and works whether or not your internet is up.

Yes — push notifications are sent to every paired phone the moment a leak is detected. Multiple family members can be alerted at once.

Yes. You can build a rule that cuts power to specified outlets — return pump, ATO, top-off — the instant a leak is detected, stopping the source of water before more damage is done.

• → Read: Leak detection guide
• → Safety and certifications

Cut power to pumps and the ATO, locate the source, and contain the spill. If the cause isn’t obvious, look at silicone seams, plumbing joints, and overflow plumbing first. Tank Commander can perform the pump shutoff automatically.

Yes. Sump baffles can crack, pumps and check valves fail, and RO/DI line connections can pop loose. Place sensors near every plumbing junction and external pump.

No — sensors detect liquid water making conductive contact, not humidity. Even a sweating cabinet won’t trigger them.

Yes. You can place several sensors around your stand, sump, and floor to monitor every risk point.

The sensors are passive and last for years. They have no batteries to replace. Wipe and dry occasionally as part of routine maintenance.

Yes — that’s the entire point. Catching a leak in the first minutes gives you time to cut pumps and contain the spill before it spreads beyond a few towels’ worth of water.

It can dramatically reduce the risk by cutting power to outlets when water reaches the cabinet floor. Combined with a properly wired GFCI, it’s a strong layered defense.

The sensor reacts within seconds of water contact. The local alarm and push notification fire essentially together, so you’re informed before water can spread far.

Yes — it’s designed to. If you place a sensor where it’s normally splashed (e.g. inside the sump or under a wavemaker), expect false positives. Choose a dry placement.

The local alarm always works. Push notifications need internet at least at one end; if your home Wi-Fi is down, alerts queue and deliver as soon as it’s back. The on-device alarm is your primary defense.

Stray voltage is unwanted electrical potential in your tank water, usually leaking from an old pump, heater, or powerhead. It builds up over time and can stress fish, damage corals, and shock you when your hand goes in the tank.

• → Read: Stray voltage in aquariums explained
• → Tank Commander safety overview

Most commonly from aging seals on submersible pumps, cracked heaters, or worn powerhead motors. Less obvious sources include grounded metal framing or DC drivers near the tank with poor isolation.

Sustained stray voltage is widely linked to chronic stress, lateral-line erosion (HLLE), and unexplained livestock losses. The animals feel current you may not even notice.

• → Read: Full stray voltage guide

Yes — sticking your hand into a tank with significant stray voltage is uncomfortable and, in extreme cases, dangerous. A grounding probe drains that current safely to ground.

Head and Lateral Line Erosion is a degenerative condition in marine fish. Multiple causes have been proposed; chronic stray voltage is one of the strongest correlations seen in long-term reef tanks.

A multimeter with one probe in the water and the other on a known ground gives you a rough reading. The more reliable approach is a grounding probe on a smart outlet — it drains the voltage and lets the controller alert you when current spikes.

A grounding probe is a titanium electrode placed in the tank and electrically tied to your home ground. It gives stray current a safe path to ground instead of through your fish or your hand.

Most experienced hobbyists run one, especially on saltwater systems. It’s cheap insurance against equipment failures you can’t always see or hear.

On their own, very few. The classic objection is that a grounding probe ‘hides’ a failing piece of equipment by quietly draining its current. The right answer is to ground and monitor — Tank Commander watches current and alerts you when it climbs.

A GFCI breaks the circuit when it detects current leaking to ground — it protects you from shock. A grounding probe drains stray current safely. They’re complementary; serious tanks should have both.

Voltage is the potential difference; current is what actually flows. Both matter — high voltage with no path causes irritation; high current with a path is dangerous. Ground probes give current a safe path to leave.

It’s one of the suspects worth investigating, especially if losses are gradual and parameters look fine. Reef keepers have rescued struggling tanks just by adding a ground probe.

Internal motor windings sit very close to water, and over time small amounts of insulation degrade. Even small leakage adds up across multiple pumps in a sump or display.

A built-in grounding circuit drains stray current safely to ground via a probe in the tank. Unlike a passive ground probe, the controller also measures the current it’s draining and can alert you if it spikes — pointing you at a failing pump.

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• → Compare to Apex

Yes. When current passing through the grounding circuit climbs, you get a push notification and a local alarm so you can isolate the failing piece of equipment.

Yes — saltwater is far more conductive, so failing equipment passes more current and stray voltage is felt more strongly. Reef tanks especially benefit from grounding plus monitoring.

Definitely. Old powerheads, return pumps, and heaters are the most common culprits. Replacing equipment that’s several years old is good preventive maintenance.

It’s commonly associated with stress responses, retracted polyps, and slowed growth in sensitive species. Chronic exposure causes long-term decline.

A smart outlet is a power socket you can switch on or off from an app, on a schedule, or in response to a sensor reading. It replaces a wall timer plus a stack of Wi-Fi plugs with a single, integrated controller.

Six independently controlled outlets, all driven by the same controller and accessible from the app, the on-device display, and your automations.

• → See pricing
• → Compare to Apex

Heaters, return pumps, powerheads, wavemakers, lights, chillers, fans, ATO pumps, UV sterilizers, CO₂ solenoids, dosers, skimmers — anything you’d normally plug into a wall outlet within the per-outlet load rating.

Yes. Every outlet has its own on/off control, friendly name, schedule, and rule — they’re fully independent.

Yes — that’s the core idea. Any outlet can be tied to temperature, pH, TDS, salinity, or leak detection so the device responds to real conditions instead of just a clock.

Plug the heater into a smart outlet and add a rule like ‘cut power if temperature is above 80°F.’ It’s the simplest, most effective protection against the most common tank-killer (a stuck-on heater).

• → Read: Prevent heater failure on a reef tank
• → Setup guide

Tie the ATO outlet to your salinity reading: turn on when salinity is above target, turn off the moment it returns to target. This protects against the classic ATO failure mode of running unchecked.

• → Automating a marine tank — full guide
• → For saltwater fish-only tanks

Yes. Each outlet supports time-based schedules. For dimmable lights, you’ll typically use the light’s own ramping and just use the outlet to cut power overnight.

Yes. Tie the chiller outlet to temperature with hysteresis (e.g. on above 80°F, off at 78°F) so it doesn’t short-cycle.

Yes. Set a feed mode that turns specified outlets off for a chosen duration, then turns them back on automatically. Triggered manually from the app or the on-device display.

Yes — many users prefer their wavemaker’s own controller for fine-grained pattern control, but cycling on/off with an outlet works for simpler setups.

Yes. All schedules and parameter-driven rules run locally on the controller. Wi-Fi only matters for app access from outside your home and push notifications.

Each outlet is rated for typical aquarium gear (heaters, lights, pumps, fans). Bigger combined loads should be split across the six outlets to keep each well within spec.

Yes — the device includes built-in surge protection so a power-grid spike doesn’t take out your equipment.

Yes. The app and on-device display always let you flip an outlet on or off, with options for ‘until next schedule event’ or ‘until I switch back to auto.’

Yes. The app shows live status, current rule (auto, schedule, manual), and recent activity for every outlet.

Yes. ‘Return Pump,’ ‘Heater,’ ‘Reef Light,’ ‘ATO Pump,’ etc. — names show up everywhere from the device display to your phone.

Yes. A rule can combine conditions like ‘temperature above 80°F AND lights are on’ for finer control. Most users start simple and grow more sophisticated over time.

Yes — perhaps the most important rule of all. ‘On leak detected, cut return pump and ATO pump immediately.’ It buys you minutes that prevent floor damage.

Yes. Set a schedule for the hours you want it running, or tie it to the lighting schedule.

Yes — when power returns, outlets restore their last automated state and resume schedules immediately.

Yes. Six outlets are designed to be in use simultaneously, within typical aquarium loads.

Yes — free apps for iOS and Android that pair with your controller and stream live readings, charts, alerts, and outlet controls.

• → See product features
• → Setup guide

Live temperature, pH, TDS, salinity, leak status, stray voltage status, and the on/off state of every outlet — plus historical charts and notification settings.

Yes — both platforms are first-class. You can pair multiple phones and tablets to the same tank.

Yes. If you have several controllers, all of them appear in the app and can be viewed side by side.

Yes. You can invite family members or fish-sitters and choose whether they can view, control outlets, or change configuration.

Yes. Threshold breaches, leaks, and stray voltage spikes push a notification to your phone within seconds.

Temperature high/low, pH high/low, TDS high/low, salinity high/low, leak detected, stray voltage, outlet state changes, and connectivity loss. Each can be set per tank.

• → Continuous monitoring vs spot testing

Yes. The app shows hourly, daily, weekly, and monthly graphs so you can spot drift and seasonal patterns at a glance.

Yes — CSV export of all logged parameters is available from the app, useful for diagnosing slow trends or sharing with reef-keeping forums.

Yes. Once your controller is on Wi-Fi and the app is signed in, alerts reach you anywhere your phone has signal.

Negligibly. The app uses standard push notifications and only opens a live connection while you’re actively viewing a tank.

Yes. There’s no subscription. The app is free, updates are free, and the cloud features included with the device are free.

• → See pricing

All traffic is encrypted end-to-end. The device authenticates with the cloud and the cloud authenticates with the app — your tank is not exposed to the open internet.

Yes. Tap an outlet to toggle it on or off, override automation temporarily, or activate a feed mode.

On both iOS and Android, you can mark Tank Commander notifications as critical so they bypass silent / Do Not Disturb settings — a sensible setting for leaks and tank emergencies.

Yes. The on-device display shows live parameters and outlet states without reaching for your phone.

Temperature, pH, TDS, salinity, leak status, stray voltage status, and the on/off state of every outlet, plus alerts when something is out of range.

Yes. The values are sized so you can see them from a few meters away — a quick glance as you walk past tells you the tank is fine.

Yes. The display has a night mode that automatically reduces brightness to keep your room dark and avoid disturbing fish.

Yes. When a parameter goes out of range or a leak is detected, the display shows the alert prominently in addition to the audible alarm.

Yes. You can choose which parameters appear on the home screen and reorder them based on what matters most for your tank.

Yes — you can set quiet hours, dim it, or turn the screen off entirely while keeping audible alarms active.

Not for daily checks — the display covers that. The app adds remote access, charts, history, and away-from-home notifications. Most users use both.

Software updates delivered automatically to the device over your home Wi-Fi. They add new features, improve existing ones, and patch any issues — without you doing anything.

Yes by default. The device installs updates during a quiet window so it doesn’t interrupt active monitoring. You can also trigger an update manually from the app.

Yes. Firmware updates are free for the life of the device.

Typically a couple of minutes. The controller restarts at the end and outlets remain in their last automated state during the very brief restart.

Updates apply during a quiet window and the brief restart doesn’t interrupt outlet schedules — they resume immediately. Sensors miss only a few seconds of data.

If a release ever causes a problem, support can roll your device back to the previous firmware.

No — schedules, rules, outlet names, alert thresholds, and history all persist across updates.

The app shows a release-notes card after each update so you can see what’s new and try it right away.

Yes. Temperature, pH, and TDS are the most relevant parameters for most freshwater tanks, and the six outlets cover lights, heaters, filters, and CO₂ solenoids.

Yes. Reef keepers benefit most because salinity, temperature, pH, and stray voltage are all monitored continuously, plus the six outlets cover return pump, heater, ATO, skimmer, lights, and a wavemaker.

• → See: For reef tanks
• → Read: Automating a marine tank

Yes. Tying CO₂ to a pH threshold is a popular automation, alongside scheduled lighting and heater protection.

• → See: For planted tanks
• → Understanding pH swings in planted tanks

Yes — and it’s especially valuable for shrimp because tiny TDS or pH changes during a molt are dangerous, and continuous monitoring catches drift early.

Yes. Goldfish tanks benefit from continuous TDS monitoring (because they’re heavy bioloads) and from temperature alerts in summer.

Yes — axolotls live or die by temperature stability. Tank Commander watches it continuously and can run a fan or chiller automatically when the room warms up.

Yes. Continuous pH and temperature monitoring is ideal for hard-water rift-lake tanks, and the smart outlets handle lights, heaters, and powerheads.

Yes — for the aquatic portion. Outlets can run misters, lights, and pumps on schedules, and parameters track the water side.

Tank Commander works on tanks as small as nano (5–10 gallons). Probe placement is the only thing that gets fiddly on very small tanks.

It works on tanks up to large reef systems and beyond, limited only by per-outlet load. For massive systems, distribute loads across the six outlets.

Yes. Each tank gets its own controller; all of them appear together in the app for at-a-glance monitoring.

Reef tanks add salinity as a critical parameter, are more sensitive to temperature drift, and depend more heavily on stray voltage protection. Tank Commander handles all of this in one device.

No — the included probes work in both. You only switch the profile in the app to display the right parameter ranges and units.

Yes. Profiles let you reuse the same hardware across hobbies. Setting up a new profile takes a couple of minutes.

Yes. Continuous pH, temperature, and TDS monitoring during medication is genuinely useful — many medications affect water chemistry.

Yes. Tight temperature and pH control matters for triggering and maintaining breeding behavior in many species.

Yes. Many users place probes in the sump for the steadiest readings, since flow there is consistent and there are no fish to dodge.

Yes. The main consideration is finding a discreet probe placement — a small sump, a hidden corner, or a HOB-style chamber works well.

Yes. During cycling, watching pH and temperature continuously catches the small swings that happen as bacteria establish, and TDS alerts you to over-feeding.

Stability is the single biggest factor in reef success, and stability comes from continuous monitoring plus automation. That’s exactly the problem Tank Commander is built to solve.

Most setups are done in under 30 minutes. You mount the controller, place the probes and leak sensor, plug in your gear, and run the in-app onboarding.

• → Full setup guide — step by step

No. Probes hang in the tank or sump using included holders. No drilling, gluing, or modification is required.

On a dry surface near the tank, ideally at or above tank level so cables run cleanly. Inside the cabinet on a high mount works too, as long as it’s above the splash zone.

Probes drop into a sump or display where flow is steady, away from skimmer turbulence and direct heater output. The leak sensor sits on the cabinet floor where water would pool first.

It needs to be within reach of the probe cables and within Wi-Fi range. Most cabinets work fine; very large rooms with weak Wi-Fi may benefit from a mesh node nearby.

Just a screwdriver if you choose to mount it permanently. Many users sit it on the cabinet without mounting at all.

A standard household outlet. The controller and the six smart outlets share that single source.

Not for core monitoring, automation, or alerts on the local alarm. Internet is needed for app access from outside your home and for push notifications.

Yes. It works with any standard 2.4 GHz Wi-Fi network, including mesh setups from Eero, Google, Nest, ASUS, TP-Link, and Ubiquiti.

You re-pair the controller from the app or the on-device display. The device keeps running its automations during reconnection.

Yes — there’s a reset option on the on-device display and in the app. Useful if you change homes, sell the unit, or hit a stubborn problem.

Most often the probe is dirty or air-bound. Pull it, rinse, and reseat. If the value still won’t change, recalibrate the probe — Tank Commander walks you through it.

Either the controller has lost Wi-Fi (router rebooted, password changed) or your phone is offline. The on-device display tells you which side is the problem.

Tank Commander comes with a 2-year limited hardware warranty plus free firmware updates for the life of the device.

Currently US and Canada. International shipping is on the roadmap — sign up for the newsletter to be notified.

Orders typically leave our East-US warehouse within 5 business days. Standard shipping is 3–6 business days domestic.

30-day return policy on undamaged devices. Probes can be returned if unopened.

Yes — you can reserve a Tank Commander at the launch price with no payment today, and we’ll contact you when your unit is ready to ship.

Email support is available from inside the app and on the website. Most replies arrive within 1–2 business days.

Yes — there is a community where Tank Commander owners share rules, automations, and tank photos. New users learn faster from real setups than from documentation.

No — many beautiful tanks run with no injected CO₂ at all. CO₂ becomes useful when you want fast plant growth, demanding species (HC, Rotala, dwarf hairgrass), or a heavily lit tank. For low-tech setups with hardy plants like java fern, anubias, or crypts, ambient CO₂ is plenty.

Low-tech tanks rely on ambient CO₂, modest light, and slow growth — easy to maintain and forgiving. High-tech tanks add pressurized CO₂ injection, strong lighting, and aggressive fertilization to push plant growth and color. High-tech tanks need closer monitoring and more frequent water changes.

Plan the layout, add a nutrient-rich substrate, pour water, plant before adding fish, install your light and filter, dose ferts (and CO₂ if going high-tech), then cycle the tank for 2–4 weeks. Add livestock slowly. Continuous TDS and pH monitoring during the first month catches early problems.

Yes — and you should. Plants help kick-start the cycle by absorbing ammonia directly, and dense planting from day one suppresses algae. Add livestock only after ammonia and nitrite read zero on consecutive tests.

Most planted tanks cycle gently with plants and a small ammonia source (fish food, pure ammonia drops, or filter media from an established tank). Plants consume ammonia directly, so a true ‘mini-cycle’ may be invisible. Watch ammonia, nitrite, and continuous TDS to know when it's safe to add fish.

Diana Walstad's low-tech approach uses regular potting soil capped with gravel, heavy planting, low water flow, and minimal water changes. Plants and substrate handle most of the biological filtration. It's elegant and inexpensive, but requires patience and careful plant selection.

Aquasoils like ADA Amazonia, Tropica, and UNS Controsoil typically deliver useful nutrients for 1–2 years before becoming inert. Mature tanks compensate by adding root tabs and column dosing. The substrate's structure stays useful much longer than its nutrient content.

Aquasoils are nutrient-rich and often release ammonia for the first 2–4 weeks. This is normal and even helps the tank cycle. Do daily water changes during this period, hold off on stocking until ammonia reads zero, and keep an eye on TDS — it'll spike and slowly settle.

Aquasoils are baked, nutrient-loaded soils that lower pH and KH while feeding plant roots. Inert substrates (gravel, pool-filter sand, blasting sand) hold no nutrients and don't shift water chemistry — you supply nutrients via root tabs and column dosing instead.

Yes for heavy root feeders like Cryptocoryne, swords, and most stem plants. Push root tabs into the substrate every 2–3 months under each cluster of root-feeding plants. Stem plants and floaters that feed mostly through leaves don't need tabs.

Estimative Index, developed by Tom Barr, doses macros (N, P, K) and micros at levels deliberately above what plants can use. Weekly 50% water changes prevent build-up. EI works well in high-tech tanks because it removes nutrient limitation as a variable. Watch TDS to confirm changes are restoring baseline.

Look at the leaves: yellowing, holes, stunted growth, twisted tips, or curled edges all point to specific deficiencies. Bottom leaves yellowing usually means nitrogen; pinholes mean potassium; pale new growth often means iron or micros. A deficiency chart is the fastest diagnostic.

Older leaves yellowing first usually points to nitrogen or magnesium deficiency. Newer leaves yellowing first suggests iron or other micronutrient lock-out. Yellowing across all leaves at once can also indicate too little light or sudden parameter swings.

Pinholes that grow into larger holes are a classic potassium deficiency, especially in fast-growing stems and Amazon swords. Increase your potassium dose or switch to an all-in-one fert with adequate K. The damage doesn't reverse on existing leaves but new growth comes in clean.

Most aquarium plants are grown emersed (out of water) at the farm. Submerging them triggers a transition where emersed leaves die back and submerged leaves grow in. Trim melting leaves and be patient — within 4–6 weeks, the plant rebuilds with submerged-form leaves.

Low-tech tanks do well at 20–40 PAR at the substrate. Medium-tech runs 40–80 PAR. High-tech tanks with CO₂ can use 80–150 PAR for demanding species. PAR matters far more than wattage or lumens. Most controllable LEDs let you start low and ramp up.

Photosynthetically Active Radiation measures the light wavelengths (400–700 nm) that plants actually use for photosynthesis. Two lights with the same wattage can have very different PAR. PAR maps for popular fixtures are widely available online; pick a light with adequate PAR for your tank depth.

Six to eight hours is the sweet spot for most planted tanks. Longer photoperiods favor algae more than plants. Build up gradually if you're starting out — long photoperiods on a new, under-planted tank are a recipe for algae.

A siesta is a midday break in lighting (e.g., on 4 hours, off 4 hours, on 4 hours). Some hobbyists believe it helps reset CO₂ levels and reduce algae, though the science is debated. It often does help in high-light, no-CO₂ tanks where algae is the limiting battle.

Aim for a stable green drop checker during the photoperiod (~30 ppm CO₂). The right BPS varies by tank size, diffuser efficiency, and surface agitation — there's no universal answer. Start low and increase by 1 BPS every few days while watching fish behavior.

A drop checker is a small glass bulb filled with 4 dKH water and a pH indicator. It hangs in the tank and turns blue (low CO₂), green (~30 ppm, ideal), or yellow (too much). It lags real-time CO₂ by 1–2 hours, so use it as a slow-moving guide, not an instant readout.

Either you're not injecting enough CO₂, your diffuser is inefficient (large bubbles bypassing the water), or your indicator solution is wrong. Check the BPS, replace the drop-checker fluid, and consider an inline diffuser if a ceramic disc isn't keeping up.

Yellow means CO₂ is above ~30 ppm — into the danger zone for fish. Cut your BPS, increase surface agitation, and watch livestock for signs of distress. A yellow drop checker plus gasping fish is an emergency.

Watch fish behavior at the surface: gasping, hovering near the water line, or shrimp climbing out of the tank are warning signs. Drop checkers turning yellow, and pH crashes more than 1.0 below baseline, also indicate over-injection. A pH-tied solenoid kill switch is the safest backup.

Yes, and it happens fast. CO₂ replaces oxygen in the gill membranes; fish suffocate at the surface. A single overnight CO₂ overshoot can wipe out a tank. This is the reason every CO₂-injected tank should have an automatic kill-switch — manual valves alone aren't enough.

Fish gasping at the surface, rapid gill movement, hovering near filter outflow, color fading, and lethargy. Shrimp will climb above the waterline if they can. Bottom dwellers tip over. If you see any of these, cut CO₂ and increase surface agitation immediately.

Turn off CO₂ and add maximum surface agitation — drop airstones, point powerheads at the surface, lower the water line under the filter return. Crank a fan over the tank if you have one. Recovery usually takes 30–60 minutes with strong oxygenation.

Only during lights-on. Plants don't use CO₂ in the dark and continued injection at night drops pH dangerously. Most setups use a solenoid that turns CO₂ on 1–2 hours before lights and off shortly before lights-out. Tying the solenoid outlet to a pH threshold adds a hard safety stop.

CO₂ dissolves into water as carbonic acid, which lowers pH. A drop of 0.8–1.2 between lights-off and CO₂ peak is normal in injected tanks. Bigger drops mean either too much CO₂ or low KH (no buffering). Continuous pH logging shows the daily curve clearly.

There's a fixed mathematical relationship: CO₂ ppm ≈ 3 × KH × 10^(7−pH). At KH 4 and pH 6.6, CO₂ is roughly 30 ppm. Tables and apps make this easy to check. Stable KH gives you a reliable handle for CO₂ control.

GH measures total calcium and magnesium in the water — what most people mean when they say ‘hard’ or ‘soft’ water. GH affects shrimp molting, plant growth, and snail shell health. Test kits report it in dGH or ppm.

KH measures carbonate and bicarbonate levels — the water's buffer against pH change. Low KH lets pH swing widely; healthy KH keeps pH stable. KH and GH are different and don't move together unless you specifically use a remineralizer that addresses both.

Most planted tanks do well at GH 4–8 dGH and KH 3–6 dKH. Low-tech tanks tolerate a wider range. Shrimp tanks specifically target their species' preferred values (Caridina: GH 4–6, KH 0–1; Neocaridina: GH 6–8, KH 3–5).

Add small doses of sodium bicarbonate (baking soda) during a water change, or use a buffer designed for aquariums. Crushed coral or aragonite in the filter raises KH gradually and is harder to overshoot. Always change KH slowly — sudden swings stress livestock more than the original wrong value.

RO/DI water blended with tap, peat or alder cone in the filter, lots of leaf litter and driftwood, and patience. RO/DI gives you the cleanest baseline; tannins and organic acids lower KH gently from there. Continuous TDS and pH monitoring confirms you're staying in range.

Most tropical community fish do well between 6.5 and 7.4. Wild-caught tetras and rasboras prefer 6.0–6.8 with soft water. Tank-bred specimens are far more adaptable and tolerate harder water than their wild counterparts.

Caridina (Crystal Red, Tiger, Taiwan Bee) prefer pH 5.5–6.5 in soft water. Neocaridina (Cherry, Yellow, Blue Dream) prefer pH 6.5–7.8 in moderately hard water. Stable pH matters more than the exact target; sudden swings during top-offs are the most common shrimp killer.

Driftwood releases tannins (natural organic acids) into the water. Over weeks, these lower pH and KH. Indian almond leaves, alder cones, and oak leaves do the same thing. Some hobbyists boil new driftwood first to remove sap, others let it leach naturally.

Tannins lower pH and KH, tint water amber (the classic blackwater look), and contain natural antimicrobial compounds that benefit fish. Many soft-water species evolved in tannin-rich water and color up dramatically in it. Carbon removes tannins quickly if you don't want the look.

BBA is a stubborn red algae that grows in tufts on driftwood, slow-growing leaves, and equipment. It's fueled by inconsistent CO₂. The fix is twofold: stabilize CO₂ levels and spot-treat affected areas with liquid carbon (Excel/glut) outside the tank, or remove and treat infested objects.

GSA forms hard, round green spots on glass and slow-growing plant leaves like anubias. It's a classic phosphate-deficiency signal — counterintuitively, you fix GSA by dosing more phosphate, not less. Increase PO₄ and the spots stop forming on new growth.

GDA is a green film on glass that wipes off easily and re-forms within days. It's a juvenile algae that completes a 3–4 week life cycle. The most reliable cure is to leave it alone for the full cycle — it falls off as adult cells, gets filtered out, and doesn't return. Wiping resets the cycle.

Hair algae forms long green strands attached to plants and decor. It thrives on excess nutrients and especially excess light. The fix: reduce photoperiod, blackout (3 days lights-off, tank covered), manual removal, and add Amano shrimp or Siamese algae eaters who actually eat it.

Diatoms feed on silicates that leach from new substrate, glass, and tap water. They show up in nearly every new tank and usually disappear on their own within 2–6 weeks as silicates deplete. Otocinclus love eating them and are a great early addition.

Cyanobacteria (blue-green algae) is actually a bacteria, not algae — slimy sheets that smell earthy and pull off in mats. Caused by low flow, low nitrate, and accumulated organics. Fix flow, deep-clean substrate, blackout for 3 days, and erythromycin (chemiclean/UltraLife) treats persistent cases.

Reducing photoperiod (not necessarily intensity) helps most algae types. Dropping from 10 hours to 6 hours often shifts the balance back toward plants. Total blackouts (3 full days lights-off, tank covered) wipe out cyanobacteria and most green water.

Amano shrimp eat hair, fuzz, and BBA. Otocinclus eat diatoms and soft green film. Siamese algae eaters eat almost everything including BBA. Nerite snails eat GSA and biofilm. Avoid plecos as algae solutions — most species outgrow it and add huge bioloads.

They eat different things, so they're complementary. Amanos are aggressive eaters of hair algae, BBA, and leftover food. Otocinclus specialize in diatoms and green film on plant leaves. Most planted-tank keepers run both.

Plant heavily from day one, keep nutrient levels stable (not necessarily low), maintain a consistent photoperiod under 8 hours, change water weekly, and clean the glass on a schedule. Algae thrives on imbalance — the more stable the tank, the less algae you fight.

Stem plants: cut just above a node and replant the cut top, leaving the rooted portion to regrow. Carpet plants: trim the top half with sharp scissors to encourage horizontal spread. Anubias and ferns: cut old leaves at the rhizome. Trim before plants outgrow their spot, not after.